Sheet steel connection joints of sections consisting of sheet steel

ABSTRACT

In order to achieve a rigid connecting node of profiles ( 1, 2 ) comprising steel plate, especially a frame structure of a vehicle body from the point of view of lightweight construction, one profile ( 2 ) consisting of two parallel belts ( 2   a,    2   b ) and at least one connecting cross-piece ( 2   c,    2   d ) grips with its two ends ( 2   a*,    2   b *), which project compared with the connecting cross-piece ( 2   c,    2   d ), the other profile ( 1 ) having two parallel wall sections ( 1   a,    1   b ), wherein the belt ends ( 2   a*,    2   b *) which abut flat against the wall sections ( 1   a,    1   b ) are fixedly connected to the wall sections ( 1   a,    1   b ), for example, by means of a welded joint ( 4   a,    4   b,    4   c ). Such a connecting node offers multiple compensation for tolerances and imparts the frame structure a high stiffness.

The invention relates to a connecting node of at least two profilescomprising steel plate, especially a frame structure of a vehicle body.

Critical points of a frame structure for vehicle bodies both with regardto manufacture, and also with regard to stiffness and also with regardto durability are the so-called connecting nodes. These are points atwhich at least two profiles are interconnected. Welded joints such asare possible on closed profiles in lorry and bus construction, cannoteasily be implemented on profiles of a frame structure for private motorvehicles, which is dimensioned of steel plate using the lightweightconstruction principle, because of the thin wall thickness of the plateused for the profiles. For this reason, prefabricated nodal elements,which for example are manufactured by internal high-pressure forming ofa preformed shaped component made of steel plate (DE 196 53 509 A1), arefrequently used at the nodes. These nodal elements have connectingpieces onto which or into which the profiles of the frame structure,generally hollow profiles, can be placed. The hollow profiles placedthereon or therein can be additionally welded to the nodal element. Themanufacturing expenditure for such a frame structure is high. The weightof a frame structure manufactured using such nodal elements is alsohigher compared with a frame structure using directly connectedprofiles. Finally, these offer scarcely any possibility for compensatingfor tolerances.

The object of the invention is to develop a connecting node of a framestructure of a vehicle body which consists of profiles from the point ofview of lightweight construction, which makes it possible to achieveeasy assembly of the profiles with simple compensation of tolerances atthe connecting nodes and which exhibits a high-stiffness.

This object is solved using a connecting node of the type specifiedinitially by the fact that one profile consists of two parallel beltsand at least one connecting cross-piece and is placed with its oppositebelt ends projecting beyond the connecting cross-piece or cross-pieceson the other profile having two parallel belts or wall sections, whereinthe belt ends of one profile abut against the parallel belts or wallsections of the other profile and are thereby fixedly connected.

With the connecting node according to the invention, two profilesespecially of a frame structure of a vehicle body can easily be directlyinterconnected using different joining technologies in a simple andquick fashion. The aspect of lightweight construction has thus beentaken into account. During manufacture it is possible to achievemultiple compensation for tolerances and specifically both in the axialdirection of the profile with the belts and the connecting cross-piece,by placing it less far onto the other profile, in the axial direction ofthe other profile, by displacing it in parallel on the other profile inits axial direction, and finally with respect to the angle between thetwo profiles because no fixed solid angle is predefined unlike in thecase of the known nodal element with the connecting pieces. The designexpenditure is very low because conventional profiles are used as thestarting point only the profile with the belts and the cross-piece mustbe adapted if necessary so that the belt ends-project compared with thecross-piece. However, there are special profiles (e.g. “Davex” profiles,trademark of ThyssenKrupp Stahl AG) during whose production theprojecting length can be produced. A rigid connection can also beimplemented because as a result of the large overlap of the belt endswith the other profile, the widest possible range of joiningtechnologies alone or combined can be implemented over large areasand/or with long joining seams.

It is also advantageous to use the afore-mentioned Davex profile foranother reason. Since the cross-piece is clamped in grooves of the beltsin a Davex profile, from the point of view of optimising the loadingduring its manufacture different materials and/or different materialthicknesses can be used for the cross-piece and the belts. In addition,in the case of a Davex profile, the edge regions which project beyondthe cross-pieces at the longitudinal edges for reasons of manufacturingtechnology can be used as a support for shear panels or other functionalelements, which is not possible with other hollow profiles such astubes.

In the case of a welded joint, the weld seam can be provided at variouspoints. A first possibility involves the front edges of the projectingbelt ends. However, for reasons of the highest possible stiffness it isbetter to arrange the weld seam at the lateral edges of the projectingbelt ends. It is to be understood that the front edges can additionallybe welded on. However, it is also possible to weld the connectingcross-piece or cross-pieces of one profile to the wall section of theother profile adjacent thereto. However, this is only possibly if thecross-piece abuts against this wall section.

The connecting node according to the invention is explained in detailhereinafter with reference to the drawings which show various exemplaryembodiments. In detail in the figures:

FIG. 1 shows a view of a connecting node of two profiles of a framestructure of a vehicle body as a section of the frame structure,

FIG. 2 shows the section along the line I-I in FIG. 1 of the connectingnode from FIG. 1,

FIG. 3 shows a view of the connecting node of two profiles of a framestructure of a vehicle body in a modified design compared with FIGS. 1and 2 as a section of the frame structure and

FIG. 4 shows the section along the line II-II in FIG. 3 of theconnecting node from FIG. 3.

In the exemplary embodiment in FIG. 1 a connecting node is implementedon a profile 1 constructed as a hollow profile having a rectangularcross-section and a profile 2 formed from two belts 2 a, 2 b and twocross-pieces 2 c, 3 d connected thereto. The belts 2 a, 2 b projectbeyond the cross-pieces 2 c, 2 d with their belt ends 2 a*, 2 b*.

The profile 2 is a so-called “Davex” profile (trademark of ThyssenKruppStahl AG). A characteristic of the Davex profile is that the belts 2 a,2 b and the cross-pieces 2 c, 2 d are joined by a pure crimpedconnection and specifically the cross-pieces 2 c, 2 d are inserted ingrooves of the belts 2 a, 2 b and then crimped tightly. The use of Davexprofiles has the advantage that different materials and differentmaterial thicknesses can be selected for the belts 2 a, 2 b and thecross-pieces 2 c, 2 d with the aim of optimising the loading and weight.In addition, there is also the advantage that during manufacture thecross-pieces 2 c, 2 d should be selected as shorter than the belts 2 a,2 b so that the desired projecting length is obtained for the belt ends2 a*, 2 b*.

In both exemplary embodiments the profile 2 is connected to the profile1 via its two belt ends 2 a*, 2 b* which abut against and are welded tothe parallel side wall sections 1 a, 1 b of the profile 1. Whereas inthe exemplary embodiment in FIGS. 1 and 2 a welded seam 3 a, 3 b isapplied to the front edge of the belt-ends 2 a*, 2 b*, in the exemplaryembodiment in FIGS. 3 and 4 the welded seams 4 a, 4 b, 4 c lie on theside edges of the belt ends 2 a*, 2 b*. This position of the weldedseams 4 a, 4 b, 4 c is preferred because it gives the nodal connection ahigher stiffness. If the welded seams are located at this point, it ispossible to recess the belt ends 2 a*, 2 b* at their front edges in anarc shape. The weight of the nodal connection is thereby reduced.Another difference between the exemplary embodiment in FIGS. 3 and 4compared with that in FIGS. 1 and 2 is that the cross-pieces 2 c, 2 dreach as far as the profile 1 and are welded to said profile via a weldseam 5.

It is to be understood that as an alternative to the welded joints,soldered joints or glued joints can also be provided which can beimplemented over a large area because of the large overlap so that ahigh stiffness of the nodal connection can thereby be achieved. Inparticular however, glued joints make it possible to use variousmaterials for the profiles which cannot be welded or can only be weldedone to the other with difficulty, such as aluminium and steel forexample.

The nodal connection according to the invention allows multiplecompensation for tolerances. On the one hand, it is possible tocompensate for tolerance in the axial direction of the profile 2 byplacing this more or less far onto the profile 1. The two exemplaryembodiments show this possibility. In addition, the profile 2 can bedisplaced in parallel in the axial direction of the profile 1. Finally,different angles can also be set between the profiles 1, 2.

In any case, by means of a one-dimensional joining line between the beltends 2 a*, 2 b* of the one profile 2 and the wall sections 1 a, 1 b ofthe other profile 1 without using additional auxiliary elements, arigid, direct connection of the profiles which is simple and cheap toproduce can be achieved, which also takes into account the aspect oflight vehicle construction.

1-7. (canceled)
 8. A connecting node of at least two profiles comprisingsteel plate, especially a frame structure of a vehicle body, wherein oneprofile consists of two parallel belts and at least one connectioncross-piece and is placed with its opposite belt ends projecting beyondthe connecting cross-piece or cross-pieces in the axial longitudinaldirection of the profile on the other profile having two parallel beltsor wall sections, wherein the belt ends of one profile abut against theparallel belts or wall sections of the other profile and are therebyfixedly connected, characterised in that in the case of the profile, theconnecting cross-piece is fixedly clamped with its longitudinal edges onthe belts by bilateral crimping of the belt material.
 9. The connectingnode according to claim 8, characterized in that the fixed connectionbetween the profiles is a self-substance connection.
 10. The connectingnode according to claim 9, characterised in that the self-substanceconnection is a large-area adhesive or soldered joint between thesuperposed surfaces of the profiles.
 11. The connecting node accordingto claim 9, characterised in that the self-substance connection is awelded joint whose seam lies on the front and/or lateral edges of thebelt ends.
 12. The connecting node according to claim 11, characterisedin that the connecting cross-piece of one profile is welded to the wallsection adjacent thereto of the other profile.
 13. The connecting nodeaccording to claim 10, characterised in that in the case of a weldedseam located only at the lateral edges of the belt ends, the belt endsare recessed in an arc shape at the front edges.